Tunable multiferroic and forming-free bipolar resistive switching properties in multifunctional BiFeO3 film by doping engineering

Highlights: • Single-phase multifunctional Bi_0.94Y_0.06Fe_0.95Mn_0.05O₃ (BYFMO) film developed by doping engineering technique. • The material possesses magnetic, piezoelectric, and ferroelectric properties simultaneously in a single-phase structure. • Ferroelectric domain control under various AC tip bias voltage. • The Ag/BYFMO/FTO device exhibits forming-free bipolar resistive switching effect with high endurance and retentivity. • The Bi_0.94Y_0.06Fe_0.95Mn_0.05O₃ film has potential for future non-volatile RRAM technology. -- Abstract: The advent of multiferroic-based materials has opened the plethora for high tunable multifunctional materials and ultra-fast operation for future non-volatile memory technology. Multifunctional rhombohedral Bi_0.94Y_0.06Fe_0.95Mn_0.05O₃ (BYFMO) film is grown on fluorine-doped tin oxide to investigate the electromechanical and resistive switching properties in Ag/BYFMO/FTO RRAM configuration. UV–visible absorbance spectra reveal the semiconducting behavior of BYFMO, and the band-gap is found to be 2.37 eV. The magnetic hysteresis curve manifests the soft ferromagnetic nature by suppressing the spiral spin modulated structure, supported by MFM imaging. The Y-Mn co-doped BFO possesses highly tunable piezoelectric and ferroelectric features with maximum domains preferred along 71⁰ and 109⁰. Lateral domain growth is observed with the increase in tip bias voltage. The Ag/BYFMO/FTO RRAM shows distinct bipolar resistive switching behavior at the SET (ON), and RESET (OFF) processes are obtained at voltage V_SET = +1.7V and V_RESET = −2.8V, respectively. The memory window (ON/OFF) between high resistance state and low resistance state is about ~ 100, which can be sustained up to 100 testing cycles and 10³s without any degradation, indicating that the BYFMO based device exhibits better endurance and retention properties. Moreover, the resistive switching mechanism of the device can be well explained by space charge limited current conduction, which is well supported by conducting a filamentary model. With excellent piezoelectric and resistive switching performance, the multifunctional BYFMO has enough potential for future non-volatile memory technology.